Dioxin and related compounds are known toxic environmental pollutants and food contaminants that pose numerous serious health risks to human and wildlife populations. The aryl hydrocarbon receptor (AhR) is the biological mediator of most or all the associated toxic effects and has a high affinity for these compounds. The AhR will be a major component of a novel dioxin test under development, and accordingly, results will assess the full toxic equivalency (TEQ) for this class of chemicals. The proposed funds would support synthesis and characterization of novel label led competitor (tracer) compounds, which would be a critical component of a competitive assay system. Specifically, these aims address synthesis, purification, binding affinity, activity, specificity, and stability of several tracers. The resulting system would be used to quantify AhR-binding toxicants such as dioxins, furans, and PCBs from clinical samples such as blood, serum or tissue, food samples such as meat fat, or environmental samples such as soil or fly ash. The high throughput format of this product will dramatically reduce the time and cost of sample analysis, while providing a better assessment for health risks. PROPOSED COMMERCIAL APPLICATIONS: Medical Diagnostics, Food Testing, Environmental Testing, Drug Development, Product Toxicity Testing, Basic Research